Heat exchanger



Sept. 6, 1932..

c. o. sANDsTRoM HEAT EXCHANGER Filed Jan. 21, 1951 5 Sheets-Sheet 1 @Junren-IM" fla/ifm @a/nlbmw Sept 5 1932- c. o. sANDsTRoM 1,875,663

HEAT EXCHANGER Filed Jan. 21, 1931 n 5 Sheets-Sheet 2 sept 6, 1932.

c. o. sANDsTRoM HEAT EXCHANGER Filed Jan. 21, 1931 5 Sheets-Sheet 3 Sept .6, 1932- c. o. sANDsTROM I 1,875,663

HEAT EXCHANGER Filed Jan.. 21, 1951 5 Sheets-Sheet. 4

1*; YI A g I N AA @LGDA C C a v 1U;

In fuem'or Sept. 6, 1932.

C. O. -SANDESTROWI HEAT EX CHANGER Filed Jan. 21, 1931 5 SheeSu-Shei 5 Patented Sept. 6, 1932 UNHEDA STATES `ennemis o.- sANnsTRoM, or Los ANGELES, oisLLIFoRNIAv HEAT nxoHaNGEa ,Y

Application filed Jan-nary 21, 1931. Serial NNO. 510,203.

This invention relates to a heat exchanger.

l The conventional type of heat exchanger is a circular shell to the ends of which are welded the tube sheets. One edge of the baffling is welded to the inside of the shell and the opposite edge is kept away from the shell a distance necessary to form a passage for the circulation of the fluid. The remaining edges of the baffles fit into grooves cut'into l@ the tube sheetsg'a source of leakage, but unavoidable because of construction difliculties. It is seen that this arrangement produces a condition at the end of the pass that is unfavorable to smooth flow. The tube sheet is sometimes yextended to form a bolting flange, it being reinforced if necessary. Increased capacity is obtained by increasing the diameter ofthe shell which, in turn, necessitates increased thickness of metal in the shell.

A. flanged boiler head cover with baffles suitably cisposed provides the chambers for directing the flow through the different tube passes. The chambers formed by this baffling produces a very unfavorable condition for the flow of the fluid. In fact, this arrangement causes a large' pressure drop through the exchanger. In the larger sizes and for high pressures, the cost of plate and bolts is a large portion of the total cost of the exchanger.

It is the general object of the present invention to provide a heat exchanger in which the shell of the exchanger is formed in such a manner as to provide a smooth flowv from one baille passage to the next with a minimum of hydraulic loss, and it is a further ob-ject of the present invention to provide a heat exchanger with returnlfittings so designed as to provide a smooth flow from one tube passage to the next with a minimum of hydraulic losses, and to provideA such return fittings as are capable of being constructed in a simple and economical manner and capable of being arranged in various positions to change the number of fluid passages through the heat exchanger.

In general, the present heat exchanger is characterized by the fact that the shell of the heat exchanger is formed by curving one 'end of each baille plate and Welding the curved ends of the bafHe plates to the adjacent baille plates so that the 'curvedends of the baille platesprovide both the shell of the container y and a curved smooth flow return passage from 55' one baffle space tothe adjacent baffle space, By: this construction of the shell of the exchanger and the baffle spaces-the face of the vheat exchanger or the extent of heat exchanging surface can be increased indefnite- 1y by increasing the length ,ofthe passages or baflleplates and/thisl does not require any 'increase in the thickness of the metal. This Y is a great 'advantagein producing exchanges oflarge capacity. Moreover,the baffles may 65 y be welded to the tube sheets at intervals between the cluster of tubes and around the curved portionsfso thatl the baiiles lprovide stays for the tube sheets and relieve the tubes of any tensilestress which might induce leakage at the tube holes.

In place of the lusual expensive heavily constructed flanged boiler head for forming the return passages for ythe tubes such as are employedv in conventional heat exchangers, the heat exchanger of the present invention employs a number of return fittings, each arranged so that they may be attached to the exchanger in` various manners so that, for example, all of the clusters Vof tubes may, if desired, be arranged in Yseries to provide a long fluid passage through the exchanger or a .number of. parallel paths for passage of fluid through the tube clusters maybe prop vided soas to provide'an increased capacity 85 in the heat exchanger. Moreover, by the use of the present invention the heat exchanger may be made especially adaptable for use with liquids that foul the tubes passing through them. Because on account of the provision of parallel banks of paths forlthe fluid any one' bank or path may be'cleared outv While the others or other remains in use.

The present invention together with vari- 5 ous objects and advantages thereof will best y be understood from avdescriptionrof a preferred form or example of a heat exchanger embodying the invention. For this purpose there is hereafter described, with reference Vto the accompanying drawings, the preferred 'y l Referring to the drawings:

.thereof form or example of the heat exchanger embodying the invention.

Figure 1 is an elevation of the preferred Yform yof the heat exchanger.

Figure 2 is an enlarged elevation partially in vertical sectionV and at right angles to Figfure 1. Y 1 Y Y I n Y Figure 3 is a fragmentary vertical section through the heat exchanger showing the edge Viewr of the balfleplatesand'their' curved ends taken on line 3-3 of F lgure 4.

Figure 4 is a section on the line 4-,44'ofV Figure 3. y Y y Figure 5 is a section through'one ofthe ,tnbe'iittings takenrthrough theV longest axis :Figure -l of the Vheat exchanger withthe .heat exchanger shown'as provided with fittings ar- Vrangedein a somewhatdiiferent manner than in Figure Land with slightly inodied-forms fie of entrance fittings.l y

,ting of modifiedrear cap YFigure 7 is a section through a cap or xfita inodified'formyused when itis desired to pass the liquidlthrough each of the tubesof.eachcluster-insequence.`

` Y Figure 8 isa similar ylew of a front cap "or fitting for the same type ofexchanger as vused .with the Acap fof Figure;y i j-jFigure 9 is a similar view of a yfurther for use when it is desired topass theliquid .through the ktubes 1n a v,modified manner.

y Figure 1() is a similar view of a front cap to be used with the modifiedy rear cap shown .in `Figure 9,

Figure 11 is afront view of. a rear cap for fuse when it is desired -f to pass the liquid through tubes in a further ymodified manner.

f Figure 12 is a viewzof a front .cap forthe same modification. Y ,Y y v c Referring tothe drawingspthe heat exchanger comprises a pair `of tube'sheets 2 and 3 which extends beyond the Vshell of the vexvchanger and are Welded to the endsrof I-beam .stiffeners 4 and 5 at the topand bottom of K'Aclusters (i is disposed Within a baliie passage. The baflie passages for the exchanger as vwell as the shell of the exchanger are providthe exchanger. and 5 serve as supports on the foundation and forsupports .forjsuperimposing a plu- These Lbeam `stiffeners 4 rality of exchangers, when this isldesir'ed. 6 indicates clusters of :tubes which are arranged in` hexagonal form with a large tube ,7 in the center of the cluster. The large eentra-l tube 7 of each clusteris larger than the Vothers invorder to vaccommodate bolts 8 which hold the return fittings 9 of the exchanger in position against the tube sheets. VThe clusters or ytubes 6 are arranged in horizontal rows, as shown in Figure 1, and yeach row of tubes or ed by means of baliie plates 10, which baffle [plates are curved at one end,'as indicated `at 6 is anA elevation similar to Figure` 11, the alternate baffle plates in the exchanger being curved at opposite ends. The straight or free ends of the baiiie plates extend to approximately the center of curvature of the curved ends of t .e baffle members and the curved ends of the baflie plates are in turn welded to the adjacent upper baffle membersV at approximately the start of the curvature of such upper baffle members, as indicated at 12. The edges of the baffle members are YWelded. to the tube sheets-2 and 3 at intervals between the clusters of tubes 6 and yaround lthec-urved portions 11 so as to form tight fluid passages and to operate to hold the tube sheets in position.

In this manner the curved ends 11V lofthe baiiie members provide the outer shell of the' heat exchanger andat the same time provide 'smooth curving return passages for the baffie'spaces between adjacent baiiie members. An iniet fitting 13 is provided at the upper end of the exchanger lfor introducing fluid between the baflies at the top of the exchanger and an outlet or discharge fitting 14 is attached .to the exchanger and communicates` with the lower baffle passage. i

The return fittings 9 each comprise a body i member 15 rounded at its opposite endsas at 16 andl?, respectively, each rounded portion of the body 15 of the fittings being adapted to enclose one cluster of tubes 6 and the body 15 of the tube fittings provides a smooth connecting passage between the ends of sufficient length to Ycover the distance between the centers lof the tube clusters. At the Zhead kof each rounded portion of the bodies 15 of the fittings there is an openingl 18 and the outside of the fittings are flattened, as indisary, gasket material 2 1- inay be placed be-V tween the edges of the fittings and the tube sheets when desired.

The return fittings 9 thus described provide a simple andV economical means for connecting the dierent tube passages or clusters of tubes with each other, result-ing in aY structure more economical tol build yand lighter in weight than the usual flanged boiler head baffles used for connecting tube passages. Moreover, the return fittings are inade so as t0 provide a smoothflow for thefiuid passing from one tube cluster to another and the hydraulic lossesY of the exchanger are less than in those exchangers using the usual flanged boiler heads for this purpose. fMoreover, by providing individual tube fittings for each cluster of tubes it is possible to arrange vthe passages through the tube clusters in a great variety of manners.

` As shown in Figure l, the tube fittings are arranged so as to provide'a single passage for fluid through the tube clusters, all ofthe tube clusters being in series. However, it will be readily apparent that by connecting each row oftube clusters with the succeeding lower row of tube clusters by the tube fittings and changing the form of theinlet fittings 22 and discharging fitting 23 so that the inlet fitting 22 feedsinto the entire upper row of ltubes andthe discharge fitting 28 discharges from the entire lower row of tubes, there can be provided many parallel paths forthe fiow of fluid through the exchanger, thus permitting a greater amount of fiuid to be passed through 7 the tubes. In a similar manner by proper arrangement of the tubes fittings, Aand proper addition of inlet and outlet fittings any num-V ber of passages for fiuid may be provided.

When the exchanger is arranged to vprovide a. plurality of fiuid passages therethrough it will-be apparent that the fittings connected' with any one passage may be removed, while the fiuidis still permitted to pass through the remaining passages, and one of the passages cleared' out and again placed in series without the necessity of shutting down the exchanger.

In Figure l, 22 indicates an inlet or outlet fitting at one endof the tube passages `and 23 an inlet or outlet fitting at the other end of the tube passages; either fitting 22 or 23 may be used as an inlet and either fitting 23 or 22 may be used asthe outlet, depending on the direction that it is desired that the fluid pass through the heat exchanger, i. e. Whether the fiow is to be parallel or counter to the general direction of flow of the fluid around the tubes.

N ow referring more particularly to the modified form of the invention shown in Figure 6, we have there illustrated the ttings or caps 17 arranged sothat the fluid which passes through the clusters of tubes 6 may have'two or a greater number of passages, depending on the desire of the operator, this form of the exchanger being adapted to have a part of the exchanger shut down while the remainder continues to operate. In the form of the invention shown in Figure 6 there is shown an inlet fitting 24 connecting in the center of o-ne of the bank of tubes and a similar fitting 25 at the upper end of the ex changer which may be used for exhausting the liquid or fiuid flowing through the tube'. If the fittings or caps 24 and 25 only are used for introducing and withdrawing fluid from the tubes of the exchanger, two parallel paths of fiow will be provided in the exchanger.

-NOW referring to Figures 7 `to ll. inclusive,

modified -forms of fittings are. diagrammatically illustrated by which the fiuid may be caused to pass through the tubes'in each clus- 7 ter in differentmanners. .Y ,f

Referring to Figures 9 and l0 particularly, there are shownfittings tobe bolted against the tubesheets 2 and 3 ofthe exchanger and receive only fluid from one, cluster` of tubes. Rear caps 35 are provided and front -caps-36 are provided. `Arrows indicate the direction of flow of fluid through the tubes of thefront and rear caps 36and 35, respectively. The rear caps 35 are provided with baffles 37 in the formillustratedand the front .caps are pro` vided with bafiies '38V in the arrangementillustrated] The front capis also provided with an inlet socket 39. Vith this form of cap placed on the exchanger the fluid will flow successively through each tube of each cluster and then be transferred lto the next cluster by connecting pipes from the inlet socket'39 of one cap tothe other. In Figures 7 and 8 there is shown a rear cap 40 and a front cap 4l with bafiies 42 and 43s'o arranged that the fiuid will pass first through two tubes of a cluster, vreturning byway of three tubes of the cluster, ,and-then pass again through two tubes of the cluster before it is transferred to the next cluster .of tubes. K Y

Now referring more particularly to Figure 1l of the drawings, I `have therefillustrated a rear cap or fitting to be placed onV the exchanger when it is desired to have thefluid-v the figure there is indicateda rearV cap 44 which may be one integral cap extending across each horizontal row 0f clusters of tubes of the exchanger and is provided vonly with partitions 45 between each cluster. The corresponding front cap (shownin Figure 12) of the exchanger may also be formed integral for each horizontal rowl of cluster ofy tubes, said cap 4G-is provided,however, with fbaffies 47 which divide each cluster of tubes in two parts, one part beingmade to include the centra-l, tubes 7. Aninlet 48fis provided at one end ofthe fitting and an outlet 49 Vat the other end of the fitting. Suitable piping 50 may be provided for connecting each of the changes as come within the scope of the ap pended claims.

vI claim: f y y l. A heat exchanger comprising tube sheets tubes connecting the tube sheets, bafiie memy so.

bershaving ltheir yedges engaging the tube sheets, Vsaid-bathe -members having curved ends Whichformreturn passages for the baffle passages formed by the 'baffle members, and means Vproviding lreturn passa-ges for the tubes. l

r2. -A heat exchanger comprising tube sheets, bathe plates Vcontacting at their edgeswith the tube sheets and having one end curved, the straight ends of the-baffle members extending approximately to the centerof curvature orf-,the 'curved ends of adj acent baffle members, and the curved! ends of the baille members being secured to adjacent members, whereby there: are provided `baille passages and the curved ends of the baillemembers Yo'rm smooth-flow return passages for the baiiie passages, tubes-held by vsaidtube sheets Within the baille passages, and means for providing return passagesk for the tubes.

' A 4heat exchanger comprising tube sheets, tubes connected to 'the sheets, baille memberslhaving their edges engagingl the tube sheets, said baffle members having curved ends which are secured to the adjacent vbaffle members, each lbaffle member lhavinga straight end whichfis located at substantially the center of 'curvature of kthe curved end: of' an adjacent ba-iemember, and means for providing return passages for the tubes. v

' 4.. A heat exchanger comprising tube sheets, tubes connected to the sheets, baie members having their 'edges engaging the tube-sheets, saidba'llemembe'rshaving 'curved Y ends which are. secured tothel adjacent baille tube. sheet.

members, each. baiii'e member 'having a straight end which: is located' at substantially the center of curvature of the curved end of an adjacent baffle member, and 'individual return capsl foreach tube oluster'foperably adapted toV be separatelyV connected with the tube sheets.v 'Y

'5. A heat exchangerV comprising tube sheets, tubes connected yWith the-sheets,means providing a'baiied? exterior passa-ge for iuid to iiow around the tubes, lthe tubes being arranged.r in clusters, and individual return fittings for connecting separate clusters of tubes with an adjacent cluster of tubes.` Y

y6'. A vheat exchanger comprising tube sheets, tubes connecting.v the tube sheets, the tubes being arranged in clusters, retaining rods passing through the clusters ofi tubes, and return ttings for-individually connecting clusters of tubes together, said retaining rods operating to hold: the return fittings against the tube sheets.

7. A vheat exchanger comprising `tube J sheets, a cluster of tubes connecting the tube sheets including al relatively large central tube, a rod passing through said central tube and tube sheets, and a return itting'engagingy said rod and-held thereby against said passage 8. A heat exchanger comprising a plurality of clusters of tubes, tube sheets receiving the'tubes,means providing a `bailledfor fluida'round the exterior of the tubes, return fittings for-'the tubes adapted to connect a vsinglev cluster 'of vtubeswi-th ya single adjacent cluster of tubes, Whereby'the clustersv of tubes may be arranged in series or in a number of'parallelpaths, and Ameans for. holding the return fittingsv against the tube sheets. Y

9. A heat exchanger comprising'a plurality' of tubes, tube sheets connected With the tubes, means for provi-ding a baiiled passage for flu-id exterior'of the tubes, a plu rality of Vseparately formed return capsfor the tubes, the tubes being arranged yso 'that byattaching the return caps to 'the' tube sheets in diiierent positions certain tubes may be in somecases connected in series and Ain other cases connected invparallel, and retaining means lfor holding the return caps against the tube sheets.V

10. A 'heat exchanger comprising ltube sheets, baiiie members connected at their edge i with the tube sheets and having4 one end curved-, the straightendsfof the ballie members extending approximately to the center of curvature of the. curved ends of the adjacent baiiie members,the curved ends of the baffle members being secured tothe adjacent batliemembers, thereby providing continuously connected baffle passages in Which the curved ends of the `baille members form smooth flow return passages, tubes held by said tube sheets Within the bailie passage, and means providing return passages for the tubes, whereby the tubes may be connected together in different positions to provide various arrangementszof tube passages through the exchanger.

vSigned yat Los Angeles, California, this 141th day of January, 1931.

CHARLESv Or. SANDSTROM.

ies 

